Introduction: Sexually transmitted diseases (STD) such as gonorrhea, syphilis and ‎trichomonias are the most common infection disease in the world. Since young adults are at ‎substantial risk for contracting STD and previous studies have shown youth poor knowledge ‎level.‎

Aim: The objective of this study is to determine the knowledge level about STD among ‎Tehran University students.‎ Material and methods: This is a cross-sectional descriptive study which was conducted in ‎‏181‏‎ first-year nonmedical university students at Tehran University, Iran. Samples were chosen ‎by using random systematic sampling method and data were collected by the self-administrate ‎questionnaire. Data were analyzed by SPSS software and using chi square test.‎

 Results: Findings showed that ‎‏57.1%‏‎ had low STD knowledge and ‎‏42.9%‏‎ had moderate STD ‎knowledge. Knowledge of boys was higher than girls (p<‎‏0.0001‏‎).‎

Conclusion: According to the mentioned low level of knowledge of the university students ‎about STD and also its increased prevalence, it is suggested to teach sexual health to students ‎by their own participation and favorite educational methods.‎